Help! Before I ruin Everything

[John Hart]

I sure hope I can get some help before I have to go seek help.

Everything I turn, CRACKS. I've never had trouble with kiln dried wood, but the green stuff cracks when it dries. Even if I seal it. I know there must be something I'm missing. (especially since I don't know anything about working with non-kiln dried wood) I have a whole Pear tree and a whole cherry tree waiting for my lathe and I'd really rather not destroy it all.

Can someone give me some insight to this problem?

Thanks

[Fred LeBail]

John, I would suggest you do a search on this forum about Drying with Denatured Alcohol by Dave Smith, Longview, WA.The threads started in December of '04. It seems nearly everyone here is using some variation of his method.
When I started using this method I was still getting some cracking in some bowls,particularly Ash, but seem to have that solved now that I pay a little more attention to the wrapping of the blanks after they are soaked and turning the blank to the same thickness on the sides.
Good luck.

[John Hart]

Thanks Fred...will do

[Ernie Nyvall]

I am new here and at turning so please excuse me for asking what may be obvious to you.
Are you cutting out the pith before turning? How thin are you roughing the walls before you put up to dry and are you putting the pieces in a paper bag?
One thing I noticed happened to me was this. I have a small bowl gouge and at first I was really putting pressure on the wood and creating a lot of heat inside some of the bowls. It seemed like the ones where a lot of heat was generated, cracked as they cooled before I cud even get them in a bag. Not scientific of course.
The only other way I can see for you not to crack the wood is to send it all to me.

Ernie

[John Hart]

Ernie...You wouldn't believe how close I am to giving it all away. At least then, it will go to some good use. But I just went through the thread on Dave Smith's method of drying and got some idea of where I've been going wrong... It's amazing how you can do research and miss the obvious....But that's what I did.

But...with that said...and with what I read...I still have a question and please pardon my ignorance. Am I to understand that I should cut a blank...say 8X8X8 and just seal it with all moisture locked in. Then when I'm ready to use it, remove material, then dry it...then remove more material and dry it...and so on?

Or...do I complete the bowl and dry it. Dave's method sounds intriquing, and dispite the opposition, has molecular merit...but his thread assumed a well established knowledge of bowl turning...which I have absolutely none.

By the way...you're quite welcome to some of this pear tree if you want me to ship you a blank.

Thanks

[Mark Singer]

John,
I am really not a turner...green wood cracks. As the moisture leaves the wood it will usually crack. I would get a moisture meter and don't work the wood until it is in the 10 to 15 % moisture range.

[John Hart]

Geez...I feel stupider every minute. A moisture meter. I assume this is something that I can pick up at Rockler or is it a Home Depot item?

25 years of woodworking and never needed a moisture meter...man!!!

I joined this forum last week and I've learned more in that time than I have in the last ten years.

[Harry Pye]

John, most people rough turn their bowls, seal the end grain and allow the bowl to dry slowly (in a paper bag) for about six months. I believe the alcohol system could probably be substituted for the six month drying period.

But rough turn the bowl leaving the thickness at about 10% of the diameter or perhaps a little less. When cutting the log make two cuts, one on either side of the pith. The pith will dry the quickest, shrink and cause radial cracks in the log.

Bill Grumbine discusses this a bit on his video and also has a tutorial on cutting up a log on his web site. Since Bill is a member here you should be able to contact him easily.

Hope this helps.

[Jim Ketron]

Ok John I have been using Dave Smiths method for drying and have had great success using it. Here is what I do cut your log with no pith left in it I always cut at least an inch on each side if you do not plan to use it right away seal it up with green wood sealer (anchorseal). I usualy rough turn bowls under 10" with a 3/4 thickness add some thinkness for larger bowls soon as I rough turn it I put it in the Denatured alcohol compleatly submerged ( add weight to the inside of bowl to sink it I have been using corian) I soak My bowls for at least 24hrs more if its thicker than 3/4. after the soak take it out let the alcohol flash off then wrap it in a paper bag (Just on the outside and on the rim do not cover compleatly) use masking tape to hold the bag on tight. put it on a rack or something that will let air flow freely to the inside of the bowl ,place it rim down/bottom up I try to store it in a well ventalated room but not a hot one you want it to dry but not too fast I do this for about 2 weeks then I bring it in the house after 2 days inside the house I take the bag off then let it dry for 5 days then take it back to the lathe to finish.
I have had great luck with doing it this way.
I soak My bowls in a 5 gal bucket with a lid I keep about 2 gal in there and you can soak a bowl up to about 11" with this set up.
Give it a try
also with fruit trees they are bad to crack no matter what you do. But I have had good luck with cherry.
hope this helps
Jim

[Ernie Nyvall]

John, yes, you seal the blank with all it's moisture until you are ready to rough it out. When ready, you rough out the material down to a thickness that corresponds to the diameter of the bowl. Per Dave Smith's method 8"s or less in diameter, the wall thickness is roughed out to 1/2". Greater than an 8" diameter is roughed out to 5/8" to 3/4" walls. At this point it is dried completely by whatever method (I just started Dave Smith's method this week). Once dried it is re-chucked turned to it's final shape and thickness and finished. (It is not dried a second time per your question.)

As the bowl dries it is going to warp a bit and that is the reason not to turn it to the finished thickness on the initial cut. The extra thickness allows you to get the bowl round again.

Thanks for the generous offer of the pear blank, but I saw an opportunity to be a goof-ball and jumped at it. A sometimes bad habbit of mine.

Ernie

[Dave Smith]

Hi John,

There is an article on Wood Central with pictures which helps explain the procedure for alcohol soaking bowls. I can't post the link in the message because it would cause a catastrophic chain reaction and hasten the end of the world. You can find my web site in my profile. There is a link to the article on the home page. Please email or call me if you feel you need more help. There are a lot of people who have started using the process since I published it last November in More Woodturning. If I was English I would probably be Knighted for all the time and wood that has been saved but here I have to settle for seeing my name branded about by a lot of turning friends.

I am not sure what you were getting at about wrapping and rewraping. But after you rough turn a bowl to a fairly uniform thickness soak it in denatured ethanol alcohol. After you remove it let it dry for about an hour then wrap the outside of the bowl with heavy paper and store it upside down on a rack. If you record the date and the weight on the paper you will have an idea when the bowl is dry. A small bowl about 4" in diameter and 1/2" thick may be dry and ready to finish turn in as little as 5 days. Larger bowls with thicker walls will take longer. The atmosphere where the bowl is dried will have an effect on the drying rate. I keep my shop dehumidified and above 60 degrees year round. Alcohol has a low vapor pressure so it will flash off even in cold rooms such as a garage in Cleveland in the winter. Where a person has to be careful is drying bowls in an area with different humidity then where it will be final turned. If the bowl is not allow to acclimate it may move and change shape after it is turned. With a scale you can check the weight of a turning for several days in a row and if the weight does not change appreciably it is at equilibrium with the surrounding and ready to turn. In my opinion weight measurement is a better indicator of when a bowl is dry. Wood moisture is a function of the relative humidity so equilibrium with the surrounding can have different moisture indications. Also, weight does not have to be corrected for different woods.

You have some very good wood for turning. Both cherry and pear have been labeled problem woods. I had about a 50% failure rate with apple until I perfected the alcohol drying method. I am confident you will have good result, well at better results than you were having. Please read the article because I have left out a lot of stuff in this rambling reply.

Good luck.

Dave Smith

Not sure I said anything true but I sure said a lot in Longview, WA.

[John Shuk]

John,
An important step when setting it aside to dry I think is to put it in a paper or even plastic bag. It slows down the loss of moisture. We all want the wood to dry just not too fast.

[John Hart]

Thanks everyone for your kind and informative responses. I did look up moisture meters last night and concluded that I can not afford one at this time but I am extremely concerned about heavy moisture as I cut the trees down in the Fall and they've been in the weather all winter. I hope they are salvagable.

I have a great resource for all types of alcohols because I work at a biochemical company. The chemists use it for washing and drying their batches of stuff. It is a tried and true drying agent. Plus, I can get it for 89c a gallon.

I'm going to go slow and just try out a couple of pieces. I will also try it on a 3" diameter column for your research to see the success for large spindles. I will report back my findings. My basement shop has a very stable RH at about 60% year round so I hope that works to my advantage.

Just for fun, I was thinking about the effect of a pressurized chamber. Since the objective of the soak is to allow the alcohol to wick into the wood, putting the blank and alcohol into a sealed container and raising the pressure in the vessel by a couple of atmospheres, might allow deeper and more thorough pentetration.
Conversely, pulling a vaccuum might draw the moisture out more evenly and quicklier (quicklier?). Anyway, that's an experiement for another day, but it would mimick what the chemists do.

My thanks to Fred for pointing me to Dave's methodology..what a thread that was!
And Mark for making me aware of my target starting moisture....I would have never thunk it.
Ernie, goof-ball comment or not, the offer still stands.

Harry, I will definitely check out Bill Grumbine's tutorial. I've seen it mentioned many times so I would be a fool not to.
Jim, I can't believe you took the time to offer advice to me. Your work speaks for itself and I am grateful.
Thanks John...I think I understand now what the objective is.
I hope I didn't miss anyone.

Dave...you deserve a special thanks. It's unfortunate that you are gun-shy as a result of being the target of someone who was having a bad day. You have sacrificed your time and energy for the sole purpose of helping others. Knighted? No, I think Sainted is more appropriate. If you would like scientific findings to support your research, let me know. I have a wealth of resources at my disposal every day and I would be happy to ask questions for you.

Thanks everyone. Maybe this WILL be fun afterall.

[Jim Becker]

Controlling the rate of moisture loss is certainly important, but turning to even wall thickness is also key...especially with "fruitwoods" that already have a tendancy to move and crack. The method you use to control moisture loss doesn't matter...find the one that works for you. But your turning skills do come into place relative to even thickness and as you can see, it's not just for asthetics...the consistant thickness means less stress as the moisture also leaves the wood in a more even manner accordingly.

[Robert Cox]

John, I had to laugh at your comment about the expense of a moisture meter.

I'm very new at this stuff.

I thought the vortex stuff was a joke. Turns out it is an understatement.

I am now in the market for a bandsaw that is gonna cost me $400, at least, to support a $250 lathe!

This stuff is almost as bad as the boat!

[John Hart]

...the consistant thickness means less stress as the moisture also leaves the wood in a more even manner accordingly.

Thanks Jim...and if I may add to that, I bet that differing grain densities throughout the wood is equally important as the denser grains will retain moisture more stubbornly.

[John Hart]

This stuff is almost as bad as the boat!

Except one thing...With a boat, your happiest days are the day you buy it and the day you sell it.

Selling your tools is a sad day.:(

[Charlie Plesums]

The alcohol process makes sense chemically, but I recently saw an article "Soap in your bowl" that suggested a similar approach using dish detergent (not dishwasher soap) diluted 6:1. The article swore that turning and sanding were easier, and there was no change in the color of the wood or the way it accepted the final finsh (that part is not intuitive to me)

Links aren't allowed here, but I saw it on the Woodcraft web site, as article 313, under the wood turning topic, with the title above. It referenced an article in the AAW Spring 2002 Journal by Ron Kent and Phil Wall, and how it was documented in the techniques section of ronkent web site. It commented how it had become part of the bowl turning class at Conover Workshops. See, all those references without a link!:D

All that said, has anyone compared the alcohol and soap methods? I would rather have a bucket of soap kicking around the shop than a bucket of alcohol (even though I already have buckets of things a lot worse than alcohol).

[John Hart]

Ok guys...I went into the lab and asked the question about the nature of alcohol and it's drying effects on wood. One of the PhDs started to explain it to me, which drew a crowd of PhDs and they all started clammering at the same time and clearly enjoyed the discussion. Ends up that I think you will be very enlightened by the response. Dr. Mathys is going to write up a short dissertation on the subject and I will publish that for you when he finishes. They are all excited about an experiment they want to try in the lab. They asked me to bring in two pieces of green wood, as identical as possible and they will hook up their instrumentation to both pieces and run a series of tests with water and alcohol. The nice thing about these guys is that they are Molecular Biologists and Analytical Chemists so they are viewing this from the aspect of Vegetable Cell Structures and the transmission of energy through a cell wall. All of this is due to the tendancy of molecules to find equilibrium and the fact that wood is, in essence, a straw.

Which brings up the idea of soap as well. Through the exchange of energy, the soap would act as a dessicant as well but leave some of it's lubricant properties behind in the process. The same with salt.

But I'm stealing their thunder. I will wait for Dr. Mathys's write up on the subject and post it when I get it.

Thanks

[Robert Cox]

Nice resource to have!

I have a pet metallurgist I use the same way.

BTW, read Dave Smiths Article from his homepage link.

He talks about wrappping the outside of the bowl so that as it dries compressive stresses are induced on the inside. Thus, eliminating one source of cracking.

Oddly enough, that stress induction toward the ID is used in what pays my bills. Nuclear power.

We examine welds obsessively. There is a mthod of repair that closely mimics Daves theories.

When certain welds are found to have an ID flaw we can do a weld overlay on them. These are welds that cannot be simply redone, that opens a whole 'nother can of worms that will bite you in the butt later.

Anyway, the weld overlay is is done by laying down precise layers of weld metal over the joint with the flaw. An overlay on a 2" pipe is about 5" long and 1/3" thick.

As welds cool, they shrink. This shrinkage is ususlly bad and is one reason most welds are done in multiple passes.

In this case, the stresses induced in the base metal and the old weld are compressive. Thus removing the driving force from the flaw that needs repair.

With no driving force in the right direction, there can be no cracking.

Another method is purely mechanical. We can put a customn hydraulic clamp on the weld and squeeze it. It's a VERY big clamp!

Net effect is the same, induced compressive forces on the ID.

So there you have it, millions of daollars of engineering, reviewed and accepted by some of the toughest people opn the planet, backing up Daves theory of bowl wrapping!

[John Hart]

Hey....using billions of dollars worth of engineering to your advantage is what thievery is all about! Steal away!

Dr. Mathys also said something that you may not have thought of...He said, "I don't know anything about woodworking but if you submerged the wood in alcohol and just left it there, it would dry while submerged and it might give you more control over the process."

hmm...Now there's an experiment.

[Dave Smith]

Hi John,

I would very much like to converse with the PHDs about the alcohol process. Ask them if any of them care to email me or talk on the phone. I am not a scientist but I do have a little training and an inquisitive mind. I held a Senior Reactor Operator License and supervised shift operation of an electrical generating plant. I have talked to a few PHDs in my life. I even understood some of them. I have an accumulation of data that may be of interest to them. I am very much interested in adding technical information to substantiate my process.

As for drying of a submerged bowl. First define what is meant by drying. If it is the removal of all water molecules in the wood then successive baths in dry alcohol will be needed to displace nearly all the water in the wood. It is very difficult to remove all the water from alcohol. The common evaporation method will yield alcohol of 95% purity the rest being water. Hence the reason Everclear is often called 190 proof alcohol. I prefer to use the term dry to refer to wood being at equilibrium with its surroundings. There will still be moisture in the wood but it will not cause a problem after a vessel is finish turned.

Dave Smith

No one is minding the store as I sit at the computer in Longview, WA.

[Bob Hovde]

The alcohol process makes sense chemically, but I recently saw an article "Soap in your bowl" that suggested a similar approach using dish detergent (not dishwasher soap) diluted 6:1. The article swore that turning and sanding were easier, and there was no change in the color of the wood or the way it accepted the final finsh (that part is not intuitive to me)
....

All that said, has anyone compared the alcohol and soap methods? I would rather have a bucket of soap kicking around the shop than a bucket of alcohol (even though I already have buckets of things a lot worse than alcohol).

Charlie,

I haven't tried the alcohol method yet, but have had good luck using the soap (but at a higher concentration than 6:1). My sample is a fairly small number (couple of dozen bowls), but the color stayed fine and I had no problems with BLO or Tung Oil. I even have used (shutter) POLY on a few.

Bob

[John Hart]

Hi Dave,
Sure, I'll talk to Dr. Mathys tomorrow for you. I took the afternoon off to cut up the Cherry tree. (It's all rotted and infested with termites...total loss)
I'm sure he'll be happy, yet shy to talk to you.


As for drying of a submerged bowl. First define what is meant by drying. If it is the removal of all water molecules in the wood then successive baths in dry alcohol will be needed to displace nearly all the water in the wood. It is very difficult to remove all the water from alcohol.

Well first off, it is my guess that it would be a very bad idea to remove ALL the moisture. I assume that the moisture is a good part of the beauty of the wood. Just like an opal loses it's luster when it's water content decreases, I would be careful to control the extraction...more trial and error.

Man! I'm mad about that cherry tree! Termites...gotta hate em...I think I'll burn them and their children this weekend.

[John Hart]

Hey guys...just so you know, I've spent this past week really studying all of your advice and prepping my pear blanks just like you said. The cherry tree was termite infested but I managed to get a few blanks out of the root system. Since it snowed all day, I couldn't dig up the pear roots, so I turned a couple of bowls (rough turned like you said). All is well so far. I didn't break anything and nothing cracked...yet.

I'm readying Dave's elixer. I have a good feeling about this.

By the way...The Black Cherry burl...as I gouged into the center, I was engulfed with the smell of black cherries....I'm talking Strong!!! Holy cow!

keep ya posted...thanks!